Spinal implant with fluid delivery capabilities

ABSTRACT

A spinal implant that allows for fluid injection of material is disclosed. The implant includes a fitting with a passage and holes that are in fluid communication with the passage. The holes extend through upper and lower surfaces and/or into a central cavity of the implant. The implant allows for material to be introduced into the implant after initial implantation thereof. Methods of implanting the implant are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of the filing date of U.S.Provisional Patent Application No. 62/103,270, filed Jan. 14, 2015, thedisclosure of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to spinal surgery, namely, the fusion ofadjacent intervertebral bodies or the replacement of a vertebral body.

Back pain can be caused by many different maladies, not the least ofwhich are problems that directly impact the intervertebral discs of thespine. Typical disc issues include, inter alia, degeneration, bulging,herniation, thinning and abnormal movement. One method of treatment ofsuch disc problems that has been widely utilized in the field of spinalsurgery is a spinal fusion procedure, whereby an affected disc isremoved, and the adjacent vertebral bodies are fused together throughthe use of interbody spacers, implants or the like. In some instances,it may also be necessary to remove and replace an entire vertebral body.This is often accomplished through the use of a larger implant that actsto fuse together the vertebral bodies adjacent the removed vertebralbody.

The aforementioned implants often rely upon mechanical features toensure engagement between the devices and the bone of the existingvertebral bodies. This coupled with the normal compressive load of thespine acts to keep the implant in place until bone can grow from theexisting vertebral bodies into and through the implant. To encourage thebone growth, the implants are often pre-loaded with bone growthpromoting material and thereafter placed into the spine. Bone growthpromoting material may include naturally occurring bone, artificialmaterials or the like.

This pre-loading of bone growth promoting material normally takes placeprior to implantation of existing implants, typically on a back table ofthe operating room. This requires the surgeon or other medicalprofessional to estimate the overall amount of material to be pre-loadedinto the implant, which is often not an easy task. Moreover, thepre-loaded material can fall out of the implant during the implantationprocess. All of this has the tendency to create an inefficient surgicalprocedure.

Therefore, there exists a need for an improved spinal implant thatovercomes the aforementioned drawbacks.

BRIEF SUMMARY OF THE INVENTION

The present application discloses several embodiment spinal implantsthat allow for in situ application of a material such as cement, a bonegrowth promoting substance, BMA, biologics, antimicrobials, antibiotics,or the like. The implants in accordance with the present inventionprovide a more efficient manner of providing such substances to theintervertebral space. Although implants in accordance with the presentinvention may widely vary from what is specifically disclosed herein,the implants generally include a passage fluidly connected to holeseither on one or all of the upper and lower surfaces and interiorsurface of a cavity formed through the implant. The holes may be sizedand/or shaped to allow for uniform flow of material introduced into theimplant. While largely disclosed as an implant suitable for fusingadjacent vertebral bodies, implants in accordance with the presentinvention may be suited for replacement of a vertebral body. Likewise,although largely shown as being suitable for introduction into the bodyof a patient from a certain aspect, implants according to the presentinvention may be configured for introduction from any aspect.

A first aspect of the present invention is a spinal implant having anupper surface including a first hole, a lower surface including a secondhole a cavity formed through the upper and lower surfaces, the cavityincluding a third hole and a fitting including a passage in fluidcommunication with the first, second and third holes.

Other embodiments of the first aspect may vary from the foregoing. Forinstance, the spinal implant may further include a plurality of first,second and third holes, a manifold in fluid communication with thepassage, a first channel in fluid communication with the manifold andthe first holes and a second channel in fluid communication with themanifold and the second holes. The first and second channels may becurved, as may the manifold be curved. The first holes, second holes,first channel and second channel may increase in size as they extendfurther away from the passage. The third holes may be in fluidcommunication with the manifold and at least one of the first and secondchannels. The implants may further have a porous structure at the upperand/or lower surfaces. In certain embodiments, the fitting may be a maleluer fitting. An insertion tool may be engaged with the fitting. Thespinal implants of the first aspect may be designed to be implanted fromvarious aspects of a patient, including from an anterior aspect of apatient. The passage, the manifold, the first channel, the secondchannel and the first and second holes may be included in a fluidtransfer structure. That structure may be formed separately from aremainder of the implant. The implant may further include sidewalls withwindows formed therethrough, the windows in fluid communication with thecavity. A fourth hole and a fifth hole may be located within the windowsand in fluid communication with the passage

A second aspect of the present invention is another spinal implanthaving an upper surface including a plurality of first holes, a lowersurface including a plurality of second holes, a cavity formed throughthe upper and lower surfaces and a fitting including a passage in fluidcommunication with the first and second holes.

Other embodiments according to the second aspect may include a manifoldin fluid communication with the passage, a first channel in fluidcommunication with the manifold and the first holes and a second channelin fluid communication with the manifold and the second holes. Aplurality of third holes may be in fluid communication with the cavity.

A third aspect of the present invention is yet another spinal implanthaving an upper surface, a lower surface, a cavity formed through theupper and lower surfaces, the cavity including a plurality of holes anda fitting including a passage in fluid communication with the holes.

In another embodiment according to the third aspect, the upper surfacemay include a plurality of second holes and the lower surface mayinclude a plurality of third holes.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the subject matter of the presentinvention and of the various advantages thereof can be realized byreference to the following detailed description in which reference ismade to the accompanying drawings in which:

FIG. 1A is a perspective view of an implant according to one embodimentof the present invention.

FIG. 1B is a side view of the implant of FIG. 1A.

FIG. 1C is a rear view of the implant of FIG. 1A.

FIG. 1D is a top view of the implant of FIG. 1A.

FIG. 1E is a cross-sectional view of the implant of FIG. 1A taken alongline 1E-1E of FIG. 1D.

FIG. 1F is a front view of the implant of FIG. 1A.

FIG. 1G is a cross-sectional view of the implant of FIG. 1A take alongline 1G-1G of FIG. 1F.

FIG. 2A is a top view of an implant according to another embodiment ofthe present invention.

FIG. 2B is a cross-sectional view of the implant of FIG. 2A take alongline 2B-2B.

FIG. 2C is a front view of the implant of FIG. 2A.

FIG. 2D is a cross-sectional view of the implant of FIG. 2A take alongline 2D-2D of FIG. 2C.

FIG. 3A is a top view of an implant according to another embodiment ofthe present invention.

FIG. 3B is a cross-sectional view of the implant of FIG. 3A take alongline 3B-3B.

FIG. 3C is a front view of the implant of FIG. 3A.

FIG. 3D is a cross-sectional view of the implant of FIG. 3A take alongline 3D-3D of FIG. 3C.

FIG. 4A is a perspective view of an implant according to anotherembodiment of the present invention.

FIG. 4B is a top view of the implant of FIG. 4A.

FIG. 4C is a rear view of the implant of FIG. 4A.

FIG. 4D is a cross-sectional view of the implant of FIG. 4A taken alongline 4D-4D of FIG. 4C.

FIG. 5A is a perspective view of an implant according to anotherembodiment of the present invention.

FIG. 5B is a front view of the implant of FIG. 5A.

FIG. 5C is a cross-sectional view of the implant of FIG. 5A taken alongline 5C-5C of FIG. 5B.

FIG. 5D is a side view of the implant of FIG. 5A.

FIG. 5E is a cross-sectional view of the implant of FIG. 5A take alongline 5E-5E of FIG. 5D.

FIG. 6A depicts placement of an implant according to the presentinvention between adjacent vertebrae of the spine.

FIG. 6B is a cross-sectional view of the placement depicted in FIG. 6A.

FIG. 6C is an enlarged cross-sectional view of the placement shown inFIG. 6B.

FIG. 6D is a cross-sectional view of an implant according to the presentinvention engaged with an insertion tool.

FIG. 6E depicts removal of an insertion tool subsequent to placement ofan implant according to the present invention between adjacentvertebrae.

FIG. 6F illustrates an implanted implant according to the presentinvention subsequent to injection of a fluid or material therein.

FIG. 6G is an x-ray view of the implant of FIG. 6F.

FIG. 7A illustrates a 3D printed implant according to another embodimentof the present invention with an insertion instrument attached thereto.

FIG. 7B illustrates a 3D printed implant according to another embodimentof the present invention.

FIG. 8A is a perspective view of another implant embodiment of thepresent invention.

FIGS. 8B-8C depict yet another implant embodiment of the presentinvention.

FIG. 8D depicts yet another implant embodiment of the present invention.

FIGS. 9A-9B depict yet another implant embodiment of the presentinvention.

FIGS. 10A-10B depict yet another implant embodiment of the presentinvention.

FIGS. 11A-11B depict yet another implant embodiment of the presentinvention.

FIGS. 12A-12C depict yet another implant according to another embodimentof the present invention.

FIG. 13 is a cross-sectional view of an implant according to yet anotherembodiment of the present invention.

DETAILED DESCRIPTION

An implant 10 according to a first embodiment of the present inventionis depicted in FIGS. 1A-1G. Implant 10 is shown as an implant suitablefor implantation from an anterior aspect of a patient. However, as willbe readily apparent from the below discussion pertaining to otherembodiments, the present invention is not limited to any particular typeof implant design. Rather, it is contemplated that certain features ofthe present invention can be implemented in different types of implants.For instance, implants according to the present invention can be adaptedfor implantation from posterior, lateral, posterior-lateral aspects orthe like of the patient. Moreover, implants according to the presentinvention may be constructed of different types of materials that areboth biocompatible and suitable to withstand the natural forces of thehuman spine. For instance, it is contemplated that implants according tothe present invention may be constructed of metallic materials such astitanium, polymeric materials such as PEEK or the like.

Implant 10 is shown including upper and lower surfaces 12 and 14,respectively. Each surface includes a plurality of holes 16 formedtherethrough, although the overall number of holes and their shape mayvary depending upon the particular implant and its overall size. Implant10 also includes a central cavity 18 formed through a central portion ofthe implant and through each of surfaces 12 and 14. Cavity 18 can besized and shaped differently from what is shown and can be located inother locations of implant 10. The interior of cavity 18 also includes aplurality of holes 20, which like holes 16 may vary in overall numberand shape. It is also contemplated to include more than one cavitythrough the upper and lower surfaces of the implant.

Implant 10 also includes a luer fitting 22 formed in a front portionthereof. In other embodiments, a different type of fitting may beutilized (e.g., threaded, snap-fit, etc. . . . ). Fitting 22 is designedto be engaged by a similarly designed insertion tool (discussed below)and includes a passage 24. As shown in FIG. 1E, passage 24 leads to amanifold 26 fluidly connected with holes 16 and 20. In particular, as isshown in FIGS. 1E and 1G, manifold 26 is connected to holes 16 and 20through a series of internal passages (a single flow channel 28 is shownin FIG. 1G, while two channels 28 and 29 are shown in FIG. 1E), so thatmaterial introduced through passage 24 can ultimately pass through holes16 and 20. It is to be understood that manifold 26 actually connectswith the two flow channels 28, 29, such that channel 28 is in fluidcommunication with holes 16 on upper surface 12 and channel 29 is influid communication with holes 16 on lower surface 14. The channels arealso in fluid communication with holes 20 on the interior of cavity 18.This allows for bone growth promoting material, cement or the like to beintroduced after implantation of implant 10, which in turn allows forboth an easier implantation procedure and better application of thematerial to the surgical site.

FIGS. 2A-2D depict a second embodiment implant 110. Because of thesimilarities of implant 110 to above-discussed implant 10, likereference numerals will be utilized to describe like elements, albeitwithin the 100-series of numbers. For instance, implant 110 includes anupper surface 112, a lower surface 114, a cavity 118, openings 120, afitting 122 and a passage 124. The major difference between implants 10and 110 is that the latter does not include any holes through its upperand lower surfaces 112, 114. Thus, any material introduced throughpassage 124 only extends into cavity 118. This type of design results inan implanted implant more akin to traditional spinal implants, i.e., onein which grafting material or the like is only included in a centralcavity or the like. Like implant 10, implant 110 includes a manifold 126and flow channels 128, 129. Also like implant 10, implant 110 isdesigned to be implanted from an anterior aspect of a patient. Ofcourse, implant 110, like all embodiment implants disclosed in thepresent application, could be configured for implantation from otheraspects, as well as could exhibit different overall shapes and/or sizesand in its individual features.

FIGS. 3A-3D depict yet another embodiment implant 210. As with implant110, like elements included in implant 210 will be identified with likereference numerals within the 200-series of numbers. Contrary to implant110, implant 210 only includes holes 216 through upper and lowersurfaces 212, 214. There are no holes included within cavity 218.Therefore, material introduced through passage 224 only extends to thoseupper and lower surfaces. Implant 210 is best suited for situations inwhich the implant is to be cemented in place between vertebral bodies.Cement injected through passage 224 extends to the interface betweenupper and lower surfaces 212, 214 and the vertebrae. Cavity 218 couldseparately be packed with bone growth promoting materials or the like,but such is up to the surgeon. It is also contemplated to provide animplant 210 without a cavity 218. Such an embodiment could includeadditional holes 216 on its upper and lower surfaces 212, 214.

FIGS. 4A-4D depict yet another embodiment implant 310, which is closestin design to implant 210. Implant 310 only includes holes 316 formedthrough its upper and lower surfaces 312, 314, with none being formed incavity 318. However, holes 316, as well as flow channel 328 exhibitvarying sizes. More specifically, holes 316 and flow channel 328increase in size as they progress from passage 324. This increase insize is aimed at ensuring balanced fluid flow. In other words, thedesign is such that each of holes 316 get the same amount of fluid flowof material, thus ensuring even distribution of cement or othermaterials introduced through passage 324. Of course, the same conceptmay be employed in implants like above discussed implants 10, 110, whereholes also extend into the central cavities of the implants.

FIGS. 5A-5E depict a PLIF-style (i.e., best suited for implantation froma posterior lateral aspect of a patient) implant 410 in accordance withthe present invention. This is one example of how the overall implantdesign can vary from those anterior implants that are described above.Aside from the overall difference in shape, implant 410 includes aninternally threaded passage 424 in lieu of a luer fitting or the like.Otherwise, implant 410 provides the similar functionality to that ofabove-discussed implant 210. Of course, any of the aforementionedvariations could be applied to implant 410. For instance, cavity 418could include holes in fluid communication with passage 424.

The use of implants according to the present invention is depicted inFIGS. 6A-6G. For ease of describing the method of use, implant 10 willbe referred to. However, it is contemplated that any of theabove-described implants, or variations thereof, could be utilized insuch use. As shown in FIG. 6A implant 10 is first connected with aninsertion tool 50. The latter is designed so as to rigidly engageimplant 10, including, for instance, a female luer fitting 52 (bestshown in FIGS. 6B-6D). Tool 50 also includes an internal passage 54 forallowing material to be introduced through passage 24 of implant 10 whenthe tool is connected thereto. Although tool 50 is depicted as includinga threaded end opposite to fitting 52, many different configurations arecontemplated. Essentially, tool 50 must be connected, either removablyor integral with a source of material. Many different designs for suchconnection are contemplated, as are the sources that provide thematerial. For instance, it is contemplated to provide a source ofmaterial that is pressurized or capable of being pressurized to allowdeployment through passage 24.

With implant 10 connected to tool 50, the latter may be manipulated toplace the former between vertebral bodies, as is shown in FIGS. 6A-6C.Although the vertebral bodies shown are naturally adjacent to oneanother, it is contemplated that implant 10 may be sized and shaped tobe placed between vertebral bodies that have become adjacent by virtueof the removal of another vertebral body. Once implant 10 is placed,material may be introduced through passage 54 of tool 50 and intoimplant 10. The above-discussed passage 24, channels 28, 29 and holes16, 20 of implant 10 allow for such material to ultimately extendthrough upper and lower surfaces 12, 14 and/or into cavity 18. FIGS. 6Fand 6G, for instance, depict an implant according to the presentinvention which has been implanted between two artificial bodies. Cementwas thereafter introduced and is shown extending through upper and lowersurfaces of the implant and into the artificial bodies. This depicts ascenario where an implant like above-discussed implant 210 is initiallyfixed in place through the use of cement. Finally, FIG. 6E depictsremoval of tool 50 from implant 10.

FIGS. 7A and 7B depict 3D printed versions of implant 210 and implant410, respectively. As shown, these versions of the implants includeporous upper and lower surfaces, as can be created through the use of a3D printing process such as is disclosed in U.S. Pat. Nos. 7,537,664 and8,147,861; U.S. Patent Application Publications Nos. 2006/0147332,2007/0142914, 2008/0004709; and U.S. patent application Ser. Nos.13/441,154 and 13/618,218, the disclosures of which are herebyincorporated by reference herein. The solid portions of the implants canalso be formed through the use of similar procedures. It is to beunderstood that creating implants according to the present invention viaa 3D printing may require that the design be modified to allow for sucha process. For instance, it is difficult, if not impossible, to create asurface directly over a void when using a 3D printing process.Therefore, the various manifolds, channels and passages may be curved orradiused to permit creation via the 3D printing process. It is alsocontemplated to form any porous region via any other suitable process,for example, a laser etching procedure.

FIG. 8A depicts an implant 510 similar to above-discussed implant 10,while FIGS. 8B-8D depict implants 610 and 710 similar to above-discussedimplant 410. As such, like reference numerals are utilized in suchfigures, where applicable. The implants of FIGS. 8A-D differ from theabove-discussed implants in that they include lateral windows 530, 630and 730, respectively, on each side of the implant. In each case, thelateral windows may allow for material introduced into the window toleach out and into the disc space. The windows may also act to reducethe overall stiffness of implants 510, 610 and 710 and to improve viewsduring an imaging process (e.g., fluoroscopy). In this regard, it iscontemplated that the windows may be tapered in a similar manner to thelordotic taper of the implant, where applicable. Furthermore, in thecase of implant 710, lateral window 730 includes holes 732. These holes,like the others discussed above, allow for material introduced into theimplant to pass therethrough.

FIGS. 9A-9B depict yet another embodiment implant 810 similar toabove-discussed implant 110. Most notably, implant 810 only includesholes 820 on an interior of cavity 818. Implant 810 also includes porousupper and lower surfaces 812, 814. The partial transparent view of FIG.9A shows the inner components (e.g., manifold 826 and channels 828,829), while the partial transparent implantation view of FIG. 9B showsthe flow of material into cavity 818 and hence the disc space. It isnoted that FIG. 9B does not include reference numerals so that the fluidflow can be fully appreciated.

FIGS. 10A-10B depict an implant 910 similar to above-discussed implant710. Implant 910 includes porous upper and lower surfaces 912, 914, aswell as lateral windows 930 with holes 932. The partial transparentimplantation view of FIG. 10B depicts the flow of material to uppersurface 912, as well as from window 930. It is noted that FIG. 10B doesnot include reference numerals so that the fluid flow can be fullyappreciated.

Implant 1010 of FIGS. 11A and 11B exhibits an overall design similar tothat disclosed in U.S. Pat. No. 8,349,015 (“the '015 Patent”), thedisclosure of which is hereby incorporated by reference herein. Inaddition to employing a stand-alone design similar to that of the '015Patent, implant 1010, like those discussed above, includes a passage1024 designed to fluidly engage an insertion tool. This allows formaterial to be introduced into implant 1010 where it is ultimatelydispersed within cavity 1018. The flow of such material is shown in thepartial transparent implantation view of FIG. 11B.

FIGS. 12A-12C depict an embodiment implant 1110, which is particularlysuited for creation via a 3D printing or additive manufacturing process.In particular, in addition to including many similar elements to thosediscussed above in connection with the foregoing embodiments, implant1110 includes a preformed fluid transfer structure 1170 (shown alone inFIG. 12C) that includes channels and holes formed therein. Thiscomponent can be created separately from the remainder of implant 1110and the can be built upon utilizing a 3D printing process or the like(see the partial hidden view of FIG. 12B). Additionally, the implant1110 and the preformed fluid transfer structure 1170 can be createdsimultaneously. Alternatively, fluid transfer structure 1170 could beformed via a similar process. Implant 1110 exhibits a remainingstructure similar to that disclosed in U.S. Provisional PatentApplication No. 62/103,276, filed Jan. 14, 2015, and the related utilityapplication filed on the same date as the present application, thedisclosures of which is hereby incorporated herein by reference. Forinstance, the implant can exhibit exterior surfaces that include bothporous and non-porous sections.

FIG. 13 depicts a cross-sectional view of yet another embodiment implant1210. As shown, passages 1224 are simply formed as triangular shapedvoids within the overall structure of the implant. It is noted thatthese passages may be in communication with holes (not shown) like thosediscussed above, or could simply allow for material to leach or pushthrough the porous material making up implant 1210. In certainembodiments, this leaching may occur only at certain locations. Implant1210 is yet another implant embodiment created utilizing a 3D printingprocess, but could of course be formed through the use of other knownmanufacturing processes.

The various embodiment implants disclosed in the present applicationmake it readily apparent that implants according to the presentinvention may vary widely while still encompassing the salient featuresof the invention. It is to be understood that not all contemplatedembodiments have been shown. It is also to be understood that thevarious embodiments may borrow certain features from each while stillremaining within the scope of the present invention. It is also to beunderstood that although it is specifically discussed herein to createimplants according to the present invention via a 3D printing likeprocess, other processes may be utilized to manufacture the implants ofthe present invention.

Although shown as distinct passages, manifolds, channels and holes, itis contemplated to provide different formations for allowing formaterial to be introduced into implants according to the presentinvention and to be dispersed therefrom. For instance, it iscontemplated to provide chambers that are in fluid communication withporous areas of the implant so that material within the chambers isallowed to pass through the porous material. The ability to includeporous material in the implants themselves may negate the need for aspecific passage/manifold/channel system. Moreover, it is contemplatedto include independent passage/manifold/channel systems within a singleimplant. This, in connection with a multi-bore insertion tool may allowfor the introduction of more than one material into the implant. Forinstance, it may be beneficial to have one material (e.g., allograft)directed to the cavity of the implant, while another material (e.g.,cement) is directed to the upper and lower surfaces. It is alsocontemplated to provide holes on an exterior surface of the variousimplants, so as to allow material to be directed from the implant. Thisallows for such material to be dispersed around the implant, which maybe beneficial in a fusion procedure. Of course, porous areas can also beincluded on the exterior of the implant to allow for same.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A spinal implant comprising: an upper surface including a first hole;a lower surface including a second hole; a cavity formed through theupper and lower surfaces, the cavity including a third hole; and afitting including a passage in fluid communication with the first,second and third holes.
 2. The spinal implant of claim 1, furtherincluding a plurality of first, second and third holes.
 3. The spinalimplant of claim 2, further including a manifold in fluid communicationwith the passage, a first channel in fluid communication with themanifold and the first holes and a second channel in fluid communicationwith the manifold and the second holes.
 4. The spinal implant of claim3, wherein the first and second channels are curved.
 5. The spinalimplant of claim 4, wherein the manifold is curved.
 6. The spinalimplant of claim 3, wherein the first holes, second holes, first channeland second channel increase in size as they extend further away from thepassage.
 7. The spinal implant of claim 3, wherein the third holes arein fluid communication with the manifold and at least one of the firstand second channels.
 8. The spinal implant of claim 1, further includinga porous structure at the upper and lower surfaces.
 9. The spinalimplant of claim 1, wherein the fitting is a male luer fitting.
 10. Thespinal implant of claim 1, further comprising a tool engaged with thefitting.
 11. The spinal implant of claim 1, wherein the implant isdesigned to be implanted from an anterior aspect of a patient.
 12. Thespinal implant of claim 3, wherein the passage, the a manifold, thefirst channel, the second channel and the first and second holes areincluded in a fluid transfer structure.
 13. The spinal implant of claim12, wherein the fluid transfer structure is formed separately from aremainder of the implant.
 14. The spinal implant of claim 1, furthercomprising sidewalls with windows, the windows in fluid communicationwith the cavity.
 15. The spinal implant of claim 14, further comprisinga fourth hole and a fifth hole located within the windows and in fluidcommunication with the passage.
 16. A spinal implant comprising: anupper surface including a plurality of first holes; a lower surfaceincluding a plurality of second holes; a cavity formed through the upperand lower surfaces; and a fitting including a passage in fluidcommunication with the first and second holes.
 17. The spinal implant ofclaim 16, further including a manifold in fluid communication with thepassage, a first channel in fluid communication with the manifold andthe first holes and a second channel in fluid communication with themanifold and the second holes.
 18. The spinal implant of claim 16,further including a plurality of third holes in fluid communication withthe cavity.
 19. A spinal implant comprising: an upper surface; a lowersurface; a cavity formed through the upper and lower surfaces, thecavity including a plurality of first holes; and a fitting including apassage in fluid communication with the holes.
 20. The spinal implant ofclaim 16, wherein the upper surface includes a plurality of second holesand the lower surface includes a plurality of third holes.